New autoantigens in rheumatoid arthritis (RA): screening 8268 protein arrays with sera from patients with RA.
OBJECTIVE
To identify new IgG autoantibodies in sera from patients with rheumatoid arthritis (RA).


METHODS
We tested serum samples from 19 patients with RA with given human leukocyte antigen (HLA)-DR genotypes, from 7 patients with spondylarthropathy, 2 patients with lupus, 4 patients with systemic sclerosis and 10 healthy individuals on 8268 human protein arrays.


RESULTS
We identified four antigens (peptidyl arginine deiminase 4 (PAD4), protein kinase Cbeta1 (PKCbeta1), phosphatylinositol 4 phosphate 5 kinase type II gamma (PIP4K2C) and v raf murine sarcoma viral oncogene homologue B1 catalytic domain (BRAF)) that were recognised almost uniquely by sera from patients with RA on protein arrays. Using purified proteins, we confirmed that PAD4 and BRAF are recognised almost uniquely by patients with RA.


CONCLUSIONS
We identified PAD4 and BRAF as RA specific autoantigens.
Auger
I
I
INSERM UMR 639, Parc Scientifique de Luminy, APHM La Conception, Marseille, France. isabelle.auger@medecine.univ-mrs.fr
Balandraud
N
N
Rak
J
J
Lambert
N
N
Martin
M
M
Roudier
J
J
D001172:Arthritis, Rheumatoid / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood* / Q000276:immunology; D001324:Autoantigens / Q000276:immunology*; D015153:Blotting, Western / Q000379:methods; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D006867:Hydrolases / Q000097:blood / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology*; D040081:Protein Array Analysis; D011493:Protein Kinase C / Q000097:blood / Q000276:immunology; D064546:Protein Kinase C beta; D000080002:Protein-Arginine Deiminase Type 4; D000076342:Protein-Arginine Deiminases; D048493:Proto-Oncogene Proteins B-raf / Q000097:blood / Q000276:immunology
D001323:Autoantibodies; D001324:Autoantigens; D007074:Immunoglobulin G; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D011493:Protein Kinase C; D064546:Protein Kinase C beta; D006867:Hydrolases; C000629235:PADI4 protein, human; D000080002:Protein-Arginine Deiminase Type 4; D000076342:Protein-Arginine Deiminases